service.startAsync().awaitRunning();
    assertEquals(State.RUNNING, service.state());

    service.stopAsync();
    service.stopAsync();
    assertEquals(State.TERMINATED, service.state());
    assertEquals(
        ImmutableList.of(State.STARTING, State.RUNNING, State.STOPPING, State.TERMINATED),
        listener.getStateHistory());
  }

    service.startAsync().awaitRunning();
    assertEquals(State.RUNNING, service.state());

    service.stopAsync();
    service.stopAsync();
    assertEquals(State.TERMINATED, service.state());
    assertEquals(
        ImmutableList.of(State.STARTING, State.RUNNING, State.STOPPING, State.TERMINATED),
        listener.getStateHistory());
  }

#         * functions;
#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
#         * compound commands having a testable exit status, especially «case»;
#         * various built-in commands including «command», «set», and «ulimit».
#
#   Important for patching:
#
#   (2) This script targets any POSIX shell, so it avoids extensions provided

     * StackOverflowError: We can't reliably call setException(error).
     *
     * - Any kind of Error from a listener. Even if we could distinguish that case (by exposing some
     * extra state from AbstractFuture), our options are limited: A call to setException() would be
     * a no-op. We could log, but if that's what we really want, we should modify

      b.append(longBitsToDouble(longs.get(i)));
      if (i == iMax) {
        return b.append(']').toString();
      }
      b.append(',').append(' ');
    }
  }

  /**
   * Saves the state to a stream (that is, serializes it).
   *
   * @serialData The length of the array is emitted (int), followed by all of its elements (each a
   *     {@code double}) in the proper order.
   */

  }

  private boolean tryToComputeNext() {
    state = State.FAILED; // temporary pessimism
    next = computeNext();
    if (state != State.DONE) {
      state = State.READY;
      return true;
    }
    return false;
  }

  @CanIgnoreReturnValue // TODO(kak): Should we remove this?
  @Override
  @ParametricNullness
  public final T next() {
    if (!hasNext()) {

    return remove(key, 0);
  }

  /**
   * Removes all mappings from this map whose values are zero.
   *
   * <p>This method is not atomic: the map may be visible in intermediate states, where some of the
   * zero values have been removed and others have not.
   */
  public void removeAllZeros() {
    map.values().removeIf(x -> x == 0);
  }

  /**

   * Returns the lexically cleaned form of the path name, <i>usually</i> (but not always) equivalent
   * to the original. The following heuristics are used:
   *
   * <ul>
   *   <li>empty string becomes .
   *   <li>. stays as .
   *   <li>fold out ./
   *   <li>fold out ../ when possible
   *   <li>collapse multiple slashes
   *   <li>delete trailing slashes (unless the path is just "/")
   * </ul>
   *

          public void failed(State from, Throwable failure) {
            assertEquals(State.RUNNING, from);
            assertEquals(error, failure);
            latch.countDown();
          }
        },
        directExecutor());
    service.startAsync();
    latch.await();

    assertEquals(0, service.numberOfTimesRunCalled.get());
    assertEquals(Service.State.FAILED, service.state());
  }

          public void failed(State from, Throwable failure) {
            assertEquals(State.RUNNING, from);
            assertEquals(error, failure);
            latch.countDown();
          }
        },
        directExecutor());
    service.startAsync();
    latch.await();

    assertEquals(0, service.numberOfTimesRunCalled.get());
    assertEquals(Service.State.FAILED, service.state());
  }